[CF611B]New Year and Old Property（dfs）

题目链接：http://codeforces.com/contest/611/problem/B

题意：给定区间[l,r]问里面有几个数二进制里只有一个0。

按数的位数搜索，如果有0出现了则只填1，最后就是结果。

#include <algorithm>
#include <iostream>
#include <iomanip>
#include <cstring>
#include <climits>
#include <complex>
#include <fstream>
#include <cassert>
#include <cstdio>
#include <bitset>
#include <vector>
#include <deque>
#include <queue>
#include <stack>
#include <ctime>
#include <set>
#include <map>
#include <cmath>
 
using namespace std;
#define fr first
#define sc second
#define cl clear
#define BUG puts("here!!!")
#define W(a) while(a--)
#define pb(a) push_back(a)
#define Rint(a) scanf("%d", &a)
#define Rll(a) scanf("%I64d", &a)
#define Rs(a) scanf("%s", a)
#define Cin(a) cin >> a
#define FRead() freopen("in", "r", stdin)
#define FWrite() freopen("out", "w", stdout)
#define Rep(i, len) for(int i = 0; i < (len); i++)
#define For(i, a, len) for(int i = (a); i < (len); i++)
#define Cls(a) memset((a), 0, sizeof(a))
#define Clr(a, p) memset((a), (p), sizeof(a))
#define Full(a) memset((a), 0x7f7f7f, sizeof(a))
#define lrt rt << 1
#define rrt rt << 1 | 1
#define pi 3.14159265359
#define RT return
#define lowbit(p) p & (-p)
#define onenum(p) __builtin_popcount(p)
typedef long long LL;
typedef long double LD;
typedef unsigned long long ULL;
typedef pair<int, int> pii;
typedef pair<string, int> psi;
typedef pair<LL, LL> pll;
typedef map<string, int> msi;
typedef vector<int> vi;
typedef vector<LL> vl;
typedef vector<vl> vvl;
typedef vector<bool> vb;


LL l, r;
LL ret1, ret2;

void dfs1(LL cur, bool flag) {
    if(cur > l) return;
    if(cur < l && flag == 1) {
        ret1++;
    }
    if(!flag) {
        dfs1(cur*2, 1);
    }
    dfs1(cur*2+1, flag);
}

void dfs2(LL cur, bool flag) {
    if(cur > r) return;
    if(cur <= r && flag == 1) {
        ret2++;
    }
    if(!flag) {
        dfs2(cur*2, 1);
    }
    dfs2(cur*2+1, flag);
}

int main() {
    // FRead();
    while(cin >> l >> r) {
        dfs1(1, 0);
        dfs2(1, 0);
        cout << ret2 - ret1 << endl;
    }
    RT 0;
}